<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>关系选择器</title>
    <style>
      /* div::first-line {
        color: lightgreen;
        font-size: 200%;
      } */
      h2::before {
        content: "]]";
        color: red;
      }
    </style>
  </head>
  <body>
    <h2>我是标题</h2>
  </body>
</html>
